Streptococcal M protein will be sequenced and analyzed for its similarity to other M proteins. In addition, M protein isolated from functional and non-functional strains based on their ability to survive in human blood will be sequenced and compared. The development of an in vitro assay for phagocytosis will be continued. Once developed, it will be used to determine the function of type-specific opsonic antibodies for group A streptococci.